The present invention relates to a heat fixing roller in an electrophotographic recording system, and more particularly to a heat fixing roller in an electrophotographic recording system having a high degree of heat radiating efficiency by providing a plurality of heat conduits within an interior portion of the heat fixing roller.
Heat fixing rollers are widely used in electrophotographic recording systems, such as laser beam printers, copying machines and facsimile machines, to securely fix developing material (i.e., toner) upon a surface of a printable medium, such as paper. To ensure proper adhesion of the toner upon the surface of the printable medium, it is essential that the heat fixing roller be pre-heated to a temperature adequate to perform the toner fixing operation. In many cases, this process of pre-heating can be unduly time consuming, thereby causing an inconvenience to a user who is waiting to use the system. Accordingly, it is quite desirable for the heat fixing roller to be capable of being rapidly heated to the temperature necessary for proper toner fixation.
One prior art reference that seeks to provide a heat fixing roller capable of rapidly reaching a predetermined operating temperature is disclosed in U.S. Pat. No. 5,426,495 entitled Image Fixing Device Having Heating Portion At One End Thereof issued to Sawamura et al. on 20 Jun. 1995. In Sawamura et al. '495, an image fixing device has a hollow cylindrical fixing roller implemented as a heat pipe, and a pressing roller held in pressing contact with the fixing roller. The fixing roller is made up of a fixing portion, and a paper nipping portion against which the pressing roller is constantly urged. This configuration purportedly promotes rapid heat conduction from a halogen heater to a working fluid filled in the heat pipe. While conventional art, such as Sawamura et al. '495, has merit in its own right, I believe that a simplier means for enhancing heat conductivity exists.